Saewoong Oh1,Il-Kwon Oh1
KAIST1
Artificial muscles have shown their value in various applications, especially in bio-inspired robotics with scales from large to small. Among many types of artificial muscles studied, shape memory alloy (SMA), has the advantage of creating high force with large deformation via simply heating and cooling. However, limited bandwidth of SMA and its corresponding slow actuation speed was troublesome due to remarkably sluggish cooling rate compared to the heating. While active cooling components such as heavy and bulky air or liquid pumps were used to increase the actuation speed, they depreciated the merit of SMA being lightweight and shape-conformable. Therefore, we focused on accelerating cooling performance under natural cooling by maximizing thermal dissipation of SMA. Specifically, Cu nanowire-forest with high thermal conductivity was directly grown on the surface of SMA which resulted with maximizing the surface-area of the SMA for increased thermal dissipation. Cu nanowire-forest grown SMA with acclerated cooling showed faster actuation compared to the bare SMA, and it was successfully applied to biomimetic with enhanced working speed.